The present invention is related to an ophthalmologic information-processing apparatus and an ophthalmologic examination apparatus that are used for examinations in the field of ophthalmology.
In the examinations used in the field of ophthalmology, there is a visual field examination for measuring the visual field of an eye. The visual-field examination is carried out for diagnosing diseases in which abnormalities of the visual field occur, such as glaucoma, retinal pigmentary degeneration, central chorioretinopathy, optic neuritis, and macular hole. Abnormalities of the visual field include stenosis, hemianopia, scotoma, and the like.
For the visual-field examination, a dynamic perimeter for measuring dynamic visual field and a static perimeter for measuring static visual field are used (e.g. cf. Japanese Unexamined Patent Publications JP-A 2000-262471, JP-A 2002-253502, and JP-A 2003-164424). The dynamic perimeter is referred to as an automated perimeter or the like. In recent years, the static perimeter has mainly been used because of an advantage thereof that it is possible to automatically carry out measurements without the need to move a visual target presented on the eye.
The static perimeter sequentially projects a spotlight onto a plurality of stimulation points of a fundus oculi of a fixed eye, makes a subject respond as to whether he/she perceives the light for each stimulation point, and records the response result (sensitivity threshold).
The plurality of stimulation points are arranged in a predetermined pattern. A typical example of the arrangement pattern of the stimulation points is one in which the stimulation points are arranged at intervals of two degrees within a ten-degree range of view from the fovea centralis (fixed position).
In addition, a perimeter comprising a function of imaging a fundus oculi image is also known (e.g. c.f. Japanese Unexamined Patent Publication JP-A2005-102946). With this perimeter, it is possible to designate a stimulation point on a fundus oculi image. In addition, it is also possible to present the stimulation points on the fundus oculi image.
The causes for abnormalities of the visual field include abnormalities in the eyeball, abnormalities of the optic nerve, abnormalities of the optic chiasm, abnormalities in areas beyond the optic chiasm, and other abnormalities (such as psychogenic disorders). Abnormalities in the eyeball may be detected as morphological abnormalities of the retina. As an apparatus for detecting the morphological abnormalities of the retina, an optical image measuring apparatus has recently been gathering attention.
The optical image measuring apparatus is an apparatus to which OCT (Optical Coherence Tomography) technology is applied. The OCT technology is a technology of using optical beams to form images that represent the surface morphology or the internal morphology of an object to be measured. Unlike X-ray CT scanner, OCT technology is not invasive to the human body, so that its development is being highly anticipated, especially in the medical field.
Japanese Unexamined Patent Publication JP-A 11-325849 discloses an optical image measuring apparatus having a configuration in which: a measuring arm scans an object by using a rotating mirror (Galvano mirror); a reference mirror is installed on a reference arm; at the exit thereof, an interference device, in which the intensity of lights emerging from the interference of light fluxes from the measuring arm and the reference arm is also analyzed by a spectroscope, is utilized; and the reference arm is provided with an apparatus for changing a reference light flux phase by discontinuous values in a stepwise fashion.
The optical image measuring apparatus disclosed in JP-A 11-325849 uses the so-called “Fourier Domain OCT technique.” In other words, the apparatus irradiates an object to be measured with a beam of low-coherence light, obtains the spectral intensity distribution of the reflected light, and performs Fourier transform thereof, thereby converting the morphology of the object to be measured in the depth direction (z direction) into an image.
Furthermore, the optical image measuring apparatus described in JP-A 11-325849 comprises a Galvano mirror for scanning optical beams (signal lights), thereby being capable of forming an image of a desired region to be measured in the object to be measured. Incidentally, this optical image measuring apparatus is adapted to scan optical beams only in one direction (x direction) perpendicular to the z direction, so that the formed image is a 2-dimensional tomographic image in the depth direction (z direction) along the scanning direction (x direction) of the optical beams.
In addition, Japanese Unexamined Patent Publication JP-A 2002-139421 discloses a technology of: forming a plurality of 2-dimensional tomographic images in the horizontal direction by scanning the signal lights in both the horizontal and vertical directions; obtaining, based on the plurality of tomographic images, 3-D tomographic information within a measurement range; and converting it into an image. Possible examples of this 3-D imaging include a method in which a plurality of tomographic images are displayed side by side in a vertical line (referred to as stack data or the like), and a method in which a 3-dimensional image is formed by applying a rendering process to a plurality of tomographic images.
Moreover, Japanese Unexamined Patent Publication JP-A 2003-543 discloses a configuration in which such an optical image measuring apparatus is applied in the field of ophthalmology.
As described above, an abnormality of the visual field and a morphological abnormality of the retina may be related to each other. Conventionally, it has been possible to individually grasp an abnormality of the visual field and a morphological abnormality of the retina, but it has not been possible to grasp the morphology of the retina at a stimulation point in a visual-field examination. Therefore, it has also not been possible to grasp an abnormality of the visual field and a morphological abnormality of the retina in the corresponding manner.
Incidentally, with the perimeter described in JP-A 2005-102946, it is possible to grasp, by referring to a fundus oculi image, in what site of the fundus oculi a visual field has been measured, but it is not possible to grasp a morphological abnormality of the retina, especially an abnormality inside the retina. Therefore, even with this perimeter, it is not possible to grasp the correspondence between an abnormality of the visual field and a morphological abnormality of the retina.
The present invention has been achieved to solve these problems, and an object thereof is to provide a technology for enabling grasp of the correspondence between the state of visual-field functions and the morphology of a retina.
In order to achieve the above object, in a first aspect of the present invention, an ophthalmologic information-processing apparatus comprises: an accepting part configured to accept a 3-dimensional image representing a morphology of a retina; a specifying part configured to specify, in the 3-dimensional image, a plurality of positions corresponding to a plurality of stimulation points in a visual-field examination; and an analyzing part configured to analyze the 3-dimensional image and find a layer thickness of the retina at each of the plurality of positions.
Further, in a second aspect of the present invention, the ophthalmologic information-processing apparatus is characterized in that: the specifying part specifies, for each of the plurality of positions, a new position related to the position; and the analyzing part analyzes the 3-dimensional image and finds the layer thickness of the retina at the new position.
Furthermore, in a third aspect of the present invention, the ophthalmologic information-processing apparatus is characterized in that: the new position is a position where a ganglion cell, which receives signals from a cone existing at the position, exists.
Still further, in a fourth aspect of the present invention, the ophthalmologic information-processing apparatus is characterized in that: the specifying part comprises a storing part configured to previously store association information that associates a position of the cone and a position of the ganglion cell, refer to the association information for each of the plurality of positions, and find the position of the ganglion cell corresponding to the position of the cone, as the new position.
Still further, in a fifth aspect of the present invention, an ophthalmologic information-processing apparatus comprises: an accepting part configured to accept a 3-dimensional image representing a morphology of a retina; a designating part configured to designate a position in the 3-dimensional image; a specifying part configured to specify a new position related to the designated position; and an analyzing part configured to analyze the 3-dimensional image and find a layer thickness of the retina at the new position.
Still further, in a sixth aspect of the present invention, the ophthalmologic information-processing apparatus is characterized in that: the new position is a position where ganglion cell, which receives signals from cone existing at the designated position, exists.
Still further, in a seventh aspect of the present invention, the ophthalmologic information-processing apparatus is characterized in that: the specifying part comprises a storing part configured to previously store association information that associates a position of the cone and a position of the ganglion cell, refer to the association information, and find the position of the ganglion cell corresponding to the designated position, as the new position.
Still further, in an eighth aspect of the present invention the ophthalmologic information-processing apparatus is characterized in that: the specifying part sets, for each of the plurality of positions, an image region including the position; and the analyzing part finds the layer thickness at two or more positions in the image region and finds the layer thickness of the retina at the positions based on the layer thickness at the two or more positions.
Still further, in a ninth aspect of the present invention, the ophthalmologic information-processing apparatus is characterized in that: the specifying part sets an image region including the new position; and the analyzing part finds the layer thickness at two or more positions in the image region, and finds the layer thickness of the retina at the new position based on the layer thickness at the two or more positions.
Still further, in a tenth aspect of the present invention, the ophthalmologic information-processing apparatus is characterized in that: the analyzing part finds an average value of the layer thickness at the two or more positions.
Still further, in an eleventh aspect of the present invention, the ophthalmologic information-processing apparatus is characterized in that: the accepting part accepts examination results of a visual-field examination; and the analyzing part comprises a comparing part configured to compare the layer thickness of the retina and the examination results, and also comprises an output part configured to output the comparison results.
Still further, in a twelfth aspect of the present invention, an ophthalmologic examination apparatus comprises: an image forming part configured to project a light onto a fundus oculi, detect the reflected light thereof, and form a 3-dimensional image representing a morphology of a retina based on the detected results; a specifying part configured to specify, in the 3-dimensional image, a plurality of positions corresponding to a plurality of stimulation points in a visual-field examination; and an analyzing part configured to analyze the 3-dimensional image and find a layer thickness of the retina at each of the plurality of positions.
Still further, in a thirteenth aspect of the present invention, the ophthalmologic examination apparatus is characterized in that: the specifying part specifies, for each of the plurality of positions, a new position related to the position; and the analyzing part analyzes the 3-dimensional image and finds the layer thickness of the retina at the new position
Still further, in a fourteenth aspect of the present invention, an ophthalmologic examination apparatus comprises: an image forming part configured to project a light onto a fundus oculi, detect the reflected light thereof, and form a 3-dimensional image representing a morphology of a retina based on the detected results; a designating part configured to designate a position in the 3-dimensional image; a specifying part configured to specify a new position related to the designated position; and an analyzing part configured to analyze the 3-dimensional image and find a layer thickness of the retina at the new position.
According to the present invention, the layer thickness of the retina at a stimulation point in a visual-field examination can be measured, so that it is possible to grasp the correspondence between the state of visual-field functions and the morphology of the retina.
In addition, according to the present invention, it is possible to specify a new position related to a designated position, and find the layer thickness of the retina at this new position. Designation of a stimulation point in a visual-field examination enables measurement of the layer thickness of the retina at the new position related to this stimulation point (e.g. a position where a ganglion cell, which receives signals from a cone of this stimulation point, exists), so that it is possible to grasp the correspondence between the state of visual-field functions and the morphology of the retina.